Method and apparatus for continuously manufacturing fastener stringer

ABSTRACT

A fastener stringer continuous manufacturing apparatus which eliminates a necessity of increasing a size of a manufacturing apparatus and is capable of chamfering attaching legs of an engaging element which is produced continuously from a metallic wire rod having a Y-shaped section, securely and accurately, without changing a load and stroke of a pressurizing hammer, the manufacturing apparatus comprises a pair of chamfering punches each of which is disposed above the pressurizing hammer at a height corresponding to a preceding engaging element implanted to a fastener tape in advance, the chamfering punch reciprocating with respect to a side face of the preceding engaging element and having a chamfering face which chamfers outer ridge portions of right and left legs of the preceding engaging element.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and apparatus for continuouslymanufacturing a fastener stringer in which a plurality of engagingelements are implanted at a predetermined interval on one side edge of afastener tape.

2. Description of the Related Art

As disclosed in, for example, Japanese Patent Application PublicationNo. 59-51813, this kind of fastener stringer is usually obtained asfollows. That is, a long metallic wire rod having a circular section ismolded so as to have a substantially Y-like shape in its lateral sectionthrough a plurality of mill rolls and cut successively with apredetermined thickness by a cutting punch and a cutting die so as toobtain individual engaging elements. An engaging head is formed into amountain-like shape by a forming punch and a forming die so as to obtainan engaging element comprising an engaging head and attaching legs(hereinafter referred to as a “wire rod engaging element”).Subsequently, the engaging elements are implanted successively to afastener tape by pressurizing the attaching legs with a pressurizinghammer.

According to the method for continuously manufacturing the fastenerstringer, the engaging elements are produced from one continuousengaging element metallic wire rod having a circular section and theengaging elements are implanted successively to the fastener tape,thereby making it possible to manufacture the fastener stringer securingan excellent productivity without any production loss. However, becausethe individual engaging elements are produced by cutting a long wire rodwith a predetermined thickness by a cutting punch, burr is alwaysgenerated on its cutting end, so that it is difficult to obtain a smoothcurved surface.

To eliminate such an inconvenience, for example, the inventor hasalready proposed an engaging element forming method as disclosed inJapanese Patent Application Laid-Open No. 8-56714. In this engagingelement forming method, a chamfering face for chamfering an outsideridge portion on a periphery of a leg is formed on a pressurizing faceof a pressurizing hammer. Then, chamfering is carried out by rolling theridge portion on an outer periphery from the leg of the engaging elementto a part of the engaging head at the same time when the engagingelement is pressurized with the pressurizing hammer.

In the meantime, in this kind of the fastener stringer continuousmanufacturing apparatus, after a main ram equipped with a cutting dieand a forming die retracts and a metallic wire rod is cut, the main ramcontinues to retract further, so that an engaging element cut by acutting punch provided on the frame is pushed forward and automaticallymoved to a position for forming a head of the engaging element into amountain-like shape by a forming punch. A pressurizing hammer supportsattaching legs of the engaging element carried to the forming die fromeither side of the engaging element. Immediately thereafter, the formingpunch descends so as to form the head of the engaging element into amountain-like shape. After the forming into the mountain-like shape isended, the main ram advances forward so as to move the engaging elementon the forming die forward to a pressurizing position. At this time, thepressurizing hammer moves obliquely forward together and starts itspressurizing operation, so that a crotch portion between the attachinglegs of the engaging element is pressed against the edge of an engagingelement implantation portion of the fastener tape, and at the same time,the pressurization of the attaching legs is completed.

Substantially at the same time when the pressurizing hammer is actuatedto pressurize the engaging element to the fastener tape, feeding of thefastener tape is started, and immediately thereafter, the main rambegins to retract again. The above-described motion of the pressurizinghammer aims at pressurizing the attaching legs of the engaging elementgradually from the engaging head toward the leg tips and securing arequired stroke length. Thus, the pressurizing hammer is formed in aparallelogram, and a pressurizing face at its inclined short side isintroduced to a sliding groove of the pressurizing hammer whichtraverses obliquely a substantially half portion of an auxiliary ram bya pressing force of the actuating face of an actuating lever swung by acam face formed on the side face of the auxiliary ram interlocking withthe motion of the main ram. Consequently, the pressurizing hammerreciprocates linearly and obliquely forward over the substantially halfportion of the ram. Here, an elastic force which presses the actuatingface of the actuating lever is always applied to the pressurizinghammer. By using this elastic force, the pressurizing hammer isretracted quickly by the retracting action of the auxiliary ram and theelastic force regardless of its large stroke length, thereby avoiding aninterference with the cutting punch securely.

However, if it is intended to chamfer at the same time when theattaching legs of the engaging element are pressurized with thepressurizing hammer as described in the above-mentioned Japanese PatentApplication Laid-Open No. 8-56714, not only a chamfered portion becomeslonger than a conventional stroke length but also a load on an operatedpressurizing hammer increases by an amount corresponding to thechamfered portion. Thus, it is necessary to further sharpen aninclination angle of a front end of the pressurizing hammer and also toincrease a swing angle of the actuating lever and further an inclinationof the aforementioned cam. This unavoidably leads to an enhancement ofthe strength of the actuating lever and an increase in size of theapparatus.

SUMMARY OF THE INVENTION

The present invention has been achieved to solve such a problem, and anobject of the invention is to provide a fastener stringer continuousmanufacturing apparatus which eliminates the necessity of increasing thesize of the apparatus and which can chamfer attaching legs of anengaging element securely and accurately without changing a load andstroke of a pressurizing hammer.

To achieve the above-described object, according to the invention, thereis provided a fastener stringer continuous manufacturing methodcomprising: a cutting step of cutting a metallic wire rod for anengaging element, the metallic wire rod molded so as to have asubstantially Y-shaped section, in a lateral direction with apredetermined thickness; a step of forming a head of the cut engagingelement into a mountain-like shape; and an engaging element implantationstep of successively implanting attaching legs of an engaging elementwhich has been formed into the mountain-like shape to a fastener tapesupplied intermittently at a predetermined pitch by pressurizing with apressurizing hammer, the method further including: a chamfering step ofchamfering an outer ridge portion of a preceding engaging elementimplanted to the fastener tape in the engaging element implantation stepwith a chamfering punch subsequent to the engaging element implantationstep.

This manufacturing method can be executed effectively by using afastener stringer continuous manufacturing apparatus of this inventionhaving the following configuration.

That is, the fastener stringer continuous manufacturing apparatus of theinvention comprises: a cutting die which reciprocates in a cuttingdirection of the metallic wire rod for the engaging element, the wirerod molded so as to have a substantially Y-shaped section; a forming diefor forming a head of the engaging element into a mountain-like shape,the forming die provided continuously on a front end in a reciprocatingdirection of the cutting die; a cutting punch which is fixed to a baseand disposed so as to freely make a sliding contact with an uppersurface of the cutting die; a forming punch for forming the head of theengaging element into the mountain-like shape, the forming punchdisposed above a mountain-like shape forming position and ascending anddescending in cooperation with the forming die; and a pressurizinghammer for successively pressurizing attaching legs of the engagingelement formed into the mountain-like shape to a fastener tape suppliedintermittently at a predetermined pitch, the apparatus furtherincluding: a pair of chamfering punches, each of which is disposed abovethe pressurizing hammer at a height corresponding to a precedingengaging element implanted to the fastener tape in advance, thechamfering punch reciprocating with respect to a side face of thepreceding engaging element and having a chamfering face which chamfersouter ridge portions of right and left legs of the preceding engagingelement.

Preferably, the reciprocation of the chamfering punch is actuated incooperation with a drive portion of the pressurizing hammer and such asactuation is carried out by an actuating lever specialized for thechamfering punch. More preferably, the actuating lever specialized forchamfering is swung by a cam face, which is formed in a same driveportion in a same manner as a pressurization actuating lever and isspecialized for chamfering, and an actuating face of the actuating leverand a driven face of the chamfering punch have inclined faces that makea sliding contact with each other, and the respective inclined faces areso constructed that the chamfering punch entirely executes a compositemotion composed of a reciprocating motion parallel to a swing directionof the actuating lever and a lateral motion in a direction perpendicularto the swing direction of the actuating lever. Additionally, theinclined driven face of the chamfering punch is always kept in anelastic contact with the inclined actuating face of the actuating leverunder pressure, so that the driven face is reciprocated with sliding onthe inclined actuating face of the actuating lever by a swing of theactuating lever.

If the feeding of a metallic wire rod is completed, a first ramadvances, so that the metallic wire rod projects from a cutting die byan amount corresponding to a predetermined thickness. Here, the firstram begins to retract and a projecting portion of the wire rod is cutwith a cutting punch, and an engaging element is moved from the cuttingdie to the forming die at a rear end stop position of the first ram. Atthis time, a top face ridge portion of an engaging head of the engagingelement is preferred to be chamfered at the same time when the engagingelement is cut out like conventionally. At this stage, pressurizinghammers are in a stopped condition and support legs of the engagingelement from both sides in order to restrict a motion of the engagingelement in a horizontal direction. Thereafter, a forming punch lowers atthe rear end stop position of the first ram and a pressure pad alsolowers so as to form the engaging head into a mountain-like shape.

When the first ram begins to advance, the pressurizing hammer isactuated to complete implantation of the engaging element. At the timeof this pressurization, a chamfering punch is also actuated to chamferthe attaching legs of a preceding engaging element implanted to thefastener tape in advance of the pressurized engaging element. Thechamfering with the chamfering punch is executed independently of thepressurization by the pressurizing hammer. Therefore, no higher loadthan necessary is applied to each of them and the stroke of thepressurizing hammer never prolongs more than that of a conventionalexample, thereby guaranteeing secure and smooth pressurization andchamfering processings.

In the engaging element implanted to the fastener tape, at least a ridgeportion on an outside cutting edge of the attaching leg is curved,thereby manufacturing a fastener stringer formed into an outer shapehaving a smooth curved face. Thus, a completed slide fastener isprovided with an excellent tactile feeling, and further, a slidingresistance of the slider decreases, thereby allowing the opening andclosing operation of the slide fastener to be executed smoothly.

In the reciprocating the chamfering punch, the pressurization actuatinglever for the pressurizing hammer, which is supported rotatably by thesame shaft as a drive shaft of the pressurizing hammer, for example,supported by the same rotary shaft, and the chamfering actuating leverfor the chamfering punch are actuated independently of each other byfirst and second cam faces which actuate in cooperation with each otherwith the main ram as a drive source. As a result, the pressurization tothe legs of the engaging element and the chamfering on the outer ridgeportion are executed by independent members. Consequently, a necessarystroke length can be secured without applying a higher load thannecessary to pressurizing and chamfering processings, and the apparatuscan withstand a long period operation. Further, in the case where theinclined face of the chamfering punch slides and moves on the inclinedface of the actuating lever specialized for chamfering work, theactuating lever specialized for the chamfering work is swung in atransverse direction of the main ram by the cam face of the drive shaftand at the same time, the chamfering punch entirely advances withkeeping its chamfering face obliquely with respect to an engagingelement implanted to the fastener tape in the time before last time.When the chamfering is completed, the actuating lever is swung in anopposite direction and at the same time, the chamfering punch returns toits original standby position quickly. The return at this time iscarried out by an elastic force of a spring or the like. Because at thistime, the chamfering punch retracts while moving laterally to thestandby position with its oblique state, interference with othersurrounding members can be avoided.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view schematically showing major portions of afastener stringer continuous manufacturing apparatus to which theinvention is applied;

FIG. 2 is a longitudinal sectional view of an engaging element formingportion of the same apparatus;

FIG. 3 is an enlarged perspective view showing specific configurationsof a pressurizing portion and a chamfering portion indicated with anarrow A in FIG. 1;

FIG. 4 is a front view of the pressurizing portion and the chamferingportion;

FIG. 5 is an explanatory diagram of an operation of a chamfering punch;

FIG. 6 is a plan view of major portions indicating rear end stoppositions of a pressurizing hammer and the chamfering punch when a thirdram is located at its retraction end stop position;

FIG. 7 is a plan view of major portions indicating advance end operationpositions of the pressurizing hammer and the chamfering punch when thethird ram is located at its advance end stop position;

FIG. 8 is a partially broken front view showing the positional relationamong a fastener stringer, the pressurizing hammer and the chamferingpunch in a situation shown in FIG. 6;

FIG. 9 is a partially broken front view showing the positional relationamong the fastener stringer, the pressurizing hammer and the chamferingpunch in a situation shown in FIG. 7; and

FIGS. 10A to 10C are explanatory views showing an example of an engagingelement before pressurizing, an engaging element after pressurizing, andan engaging element after chamfering, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of the present invention will be describedspecifically with reference to the accompanying drawings.

Here, fastener stringer continuous manufacturing method and apparatus ofthe present invention are not different from the conventional method andapparatus disclosed in Japanese Patent Application Publication No.59-51813 in that an engaging element wire rod having a substantiallyY-shaped section obtained through a rolling process is cut to athickness corresponding to a single engaging element with a cuttingpunch, its engaging head is formed into a mountain-like shape and thenthe engaging element is implanted to a required portion of a fastenertape by pressurizing attaching legs with a pressurizing hammer so as tomanufacture a fastener stringer continuously.

The most prominent feature of the present invention is not that theattaching legs L of an engaging element are chamfered at the same timewhen the attaching legs L of the engaging element are pressurized with apressurizing hammer having a chamfering face as disclosed in JapanesePatent Application Laid-Open No. 8-56714, but that a preceding engagingelement, after pressurized to the fastener tape in advance and fed up toa predetermined position from the pressurizing portion by apredetermined pitch, is chamfered independently. Further, the chamferingof the preceding engaging element is carried out at the same time whenthe engaging element is pressurized by using the same drive shaft usedfor pressurizing process.

Because the process at the pressurizing portion and the process at thechamfering portion are carried out separately, the pressurization can beexecuted with the same stroke as a conventional pressurizing strokewithout changing the stroke length of the pressurizing hammer. Further,because the chamfering is carried out with a special punch independentlyof the pressurizing, the chamfering can be carried out securely andaccurately, so that the operation of each punch is performed extremelysmoothly.

FIGS. 1 and 2 schematically show an example of major portions of thefastener stringer manufacturing apparatus according to an embodiment ofthe invention. FIG. 3 is an enlarged perspective view of major portionsof a specific configuration indicated with A in FIG. 1.

In the fastener stringer continuous manufacturing apparatus employed inthis embodiment, the details of the configuration excluding thepressurizing portion and the chamfering portion are substantially notdifferent from that of the apparatus disclosed in Japanese PatentApplication Publication No. 59-51813. Thus, outline of otherconfiguration except the pressurizing portion and the chamfering portiondescribed below is based on description of the above-describedpublication.

In these figures, a first ram 2 is supported on a base 1 through a ramguide 3 so as to freely reciprocate horizontally, and a cutting die 4and a forming die 5, the forming die forming an engaging head of anengaging element E into a mountain-like shape, are provided on the frontend portion of the first ram 2 in this order in an advancement directionof the first ram 2. The cutting die 4 has an introduction passage 4 afor introducing an engaging element irregular shape wire rod W having,for example, a Y-shaped lateral section.

A set plate 6 supported by the base 1 is disposed above the frontportion of the first ram 2, and a ram guide 7 is mounted on the setplate 6. A second ram 8 is provided on the ram guide 7 so as to becapable of moving up and down vertically with respect to the horizontalreciprocation movement of the first ram 2. A forming punch 10 forforming the engaging head of the engaging element E into a mountain-likeshape through a punch holder 9 and a pressure pad 11 for pressing bothlegs L of the engaging element E at the time of forming into themountain-like shape are mounted on the front face of the second ram 8.Further, a cutting punch 12 capable of making a sliding contact with thetop face of the front portion of the first ram 2 is fixed on the bottomend of the ram guide 7. A pair of pressurizing hammers 13 are providedobliquely on both sides of the forming die 5, and the pressurizinghammers 13 move linearly so as to nip and pressurize the attaching legsL of the engaging element E after the engaging head is formed, therebyimplanting the engaging element E to a fastener tape T. In thisindicated example, at the same time when the engaging element E ispressurized, the chamfering punches 113 are actuated so as to chamferouter ridge portions of right and left legs L′ of a preceding engagingelement E′ implanted to the fastener tape T two times before.

As shown in FIG. 1, the wire rod W for the engaging element having aY-shaped section is intermittently supplied by an amount correspondingto the thickness of a single engaging element E by feed rollers 14, 15to the wire rod insertion hole 4 a in the cutting die 4. The fastenertape T is supplied from below and guided by a tape guide 16 and theengaging elements E are attached to the fastener tape, and then thefastener tape T becomes a slide fastener stringer S. The slide fastenerstringer S is intermittently pulled up by an intermittent drive roller17 and a pressure roller 18.

A main shaft 19 is provided above the rear portion of the first ram 2,and a first ram drive cam 20, a forming punch actuating cam 21, apressurizing/chamfering actuating cam 22, a stringer feeding cam 23 anda wire rod feeding cam 24 are provided on the main shaft 19. Therespective cams 20 to 24 are respectively connected to the first ram 2,the forming punch 10, the pressurizing hammer 13 and a chamfering punch113, the intermittent drive roller 17 and the wire rod feed roller 14via cam driven mechanisms 25 to 28, and the respective members areactuated.

The cam driven mechanism 25 of the first ram 2 has a first roller 25 awhich makes a rolling contact with the first ram drive cam 20, and theroller 25 a is journaled by the rear portion of the first ram 2. Thefirst ram 2 is urged in an advancement direction by a compression spring30, and is horizontally reciprocated by a rotation of the first ramdrive cam 20. Further, the cam face of the first ram drive cam 20 is soconstructed as to stop the first ram 2 in a predetermined time at itsfront end position and rear end position.

On the other hand, the cam driven mechanism 26 of the forming punch 10comprises a second roller 26 a, a lever 26 b, a pin 26 c, and acompression spring 26 d. The second roller 26 a makes a rolling contactwith the forming punch actuating cam 21. The roller 26 a is journaled byone end of the lever 26 b, and a central portion of the lever 26 b ismounted on the apparatus main body via a shaft. The pin 26 c is attachedto the other end of the lever 26 b, and makes contact with the head ofthe second ram 8. The compression spring 26 d gives the lever 26 b back.The second ram 8 incorporates a compression spring 31 for urging the ramupward, and the lever 26 b swings by the cam 21, so that the second ram8 lowers and this returns to its original position by the compressionspring 31.

The cam driven mechanism 27 of the pressurizing hammer 13 and thechamfering punch 113 comprises, as shown in FIGS. 1 and 2, a thirdroller 27 a, a swing lever 27 b, a link 27 c, a third ram 27 d, apressurization actuating lever 27 e, and a chamfering actuating lever 27h. The third roller 27 a makes a rolling contact with thepressurizing/chamfering actuating cam 22. The swing lever 27 b supportsthe roller 27 a through a shaft at its upper end, extends downward andswings back and forth with a central portion thereof journaled by thebase 1. A central portion of the link 27 c is connected to the bottomend of the swing lever 27 b through a shaft. The front end of the link27 c is connected to the rear portion of the third ram 27 d through ashaft. A driven face of the pressurizing hammer 13 makes a contact withthe actuating face of the top portion of the pressurization actuatinglever 27 e, and a central portion of the pressurization actuating lever27 e is journaled. A driven face of the chamfering punch 113 makescontact with the actuating face of the top portion of the chamferingactuating lever 27 h, and a central portion of the chamfering actuatinglever 27 h is journaled.

As shown in FIG. 3, a first cam face 27 f and a second cam face 27 i,which are two stages vertically separated, are provided on the right andleft side faces of the front end portion of the third ram 27 d such thatthey are deflected by a required dimension in the back and forthdirection. The first and second cam faces 27 f, 27 i have a shapeextending outward as they go to the front ends, respectively. A firstcam receiver 27 g mounted on the bottom end of the pressurizationactuating lever 27 e makes an elastic contact with the first cam face 27f while a second cam receiver 27 j provided on the bottom end of thechamfering actuating lever 27 h makes an elastic contact with the secondcam face 27 i. As the third ram 27 d retracts, the first and second camreceivers 27 g, 27 j move in the right and left direction along thefirst and second cam faces 27 f, 27 i, so that the first and chamferingactuating levers 27 e, 27 h swing. When the first and chamferingactuating levers 27 e, 27 h swing, the pressurizing hammer 13 and thechamfering punch 113 are actuated. Restoration of the third ram 27 d toits original position is carried out by the compression spring 32, andalso, return operations of the first and second actuating levers 27 e,27 h and the pressurizing hammer 13 and the chamfering punch 113 arecarried out by a spring.

As shown in FIG. 1, the cam driven mechanism 28 for feeding a stringercomprises a fourth roller 28 a, a first lever 28 b and a second lever 28d. The fourth roller 28 a makes a rolling contact with the stringerfeeding cam 23. The roller 28 a is journaled by one end of the firstlever 28 b and a fifth roller 28 c is journaled by the other endthereof, and a central portion of the first lever 28 b is supported viaa shaft. The second lever 28 d swings downward by a sixth roller 28 eand is urged upward by a pulling spring 33. A transmission shaft 34 a ofthe intermittent drive roller 17, in which a single-direction clutch(not shown) is mounted on an intermediate portion thereof, is connectedto a proximal end of the second lever 28 d, so that the intermittentdrive roller 17 is intermittently rotated only in a single direction soas to feed the fastener stringer S.

The cam driven mechanism 29 for feeding a wire rod comprises: a sixthroller 29 a which makes a rolling contact with the cam 24; a slider 29 bhaving the roller 29 a supported via a shaft at one end of the slider; aratchet 29 c attached to the other end of the slider 29 b; and a ratchetwheel 29 d which is intermittently rotated only in a single directionevery predetermined angle by the ratchet 29 c. A drive gear 42 forfeeding a wire rod shown in FIG. 4 is attached to the other end of asupporting shaft 34 b of the ratchet wheel 29 d. The irregular shapemetallic wire rod W is intermittently supplied through the drive roller14 and the rolling roller 15 by an intermittent rotation of the drivegear 42. Restoration of the slider 29 b to its original position iscarried out by a compression spring 29 e.

When the advancement of the first ram 2 stops, feeding of the irregularshape metallic wire rod W is completed, so that the irregular shapemetallic wire rod W is projected over the cutting die 4 only by apredetermined thickness. In a former half of this process, theimplantation of the engaging element E to the fastener tape T iscompleted. The fastener stringer S is pulled up immediately after pairsof the pressurizing hammers 13 and the chamfering punches 113 leave thelegs L of the respective engaging elements E, E′, and when the engaginghead of the engaging element E leaves the forming die 5, the first ram 2begins to retract. Thus, the currently implanted engaging element E isnever caught by the forming die 5 which is retracted by the first ram 2.

When the first ram 2 retracts, the wire rod W is cut. At the time ofthis retraction, pulling of the fastener stringer S is completed. Whenthe first ram 2 is located at its retraction stop position, the engaginghead is formed. After implantation of the engaging element is started bythe pressurizing hammer 13 actuated from halfway of the advancement ofthe first ram 2, the first ram 2 advances up to its advancement endposition so as to complete pressurization. Before the pressurizinghammer 13 is actuated, the chamfering punch 113 is actuated, and at thesame time when the pressurizing hammer 13 implants the engaging elementE, the outer ridge portions on the legs L′ of the preceding engagingelement E′ implanted time before last to the fastener tape T ischamfered. Hereinafter, such a procedure is repeated.

Next, an example of the structure of the pressurizing portion andchamfering portion which constitute the characteristic portion of thepresent invention will be described with reference to FIGS. 3 and 4.FIG. 4 is a partially broken front view of the pressurizing portion andchamfering portion. As shown in FIGS. 3 and 4 and described previously,the pair of pressurizing hammers 13 are provided on both sides of theforming die 5, so that the pair of right and left attaching legs L ofthe engaging element E having its engaging head formed thereon arenipped and pressurized from the right and left sides so as to implantthe engaging element E to the fastener tape T. In the indicated example,at the same time when the engaging element E is pressurized, thechamfering punches 113 are actuated so as to chamfer the outer ridgeportions of the right and left legs L′ of the preceding engaging elementE′ implanted to the fastener tape T two times before.

The pressurization actuating lever 27 e is supported rotatably by afixed supporting shaft 27 k, and an actuating portion 27 e-1 extendinglonger than the top face of the first ram 2 is provided at a top end ofthe actuating lever 27 e. A front end face of the actuating portion 27 eserves as an actuating face 27 e-2 which is composed of a vertical planeextending along the back and forth direction of the first ram 2. Thepressurizing hammer 13 is constituted of a narrow lever material havinga substantially parallelogrammatic shape. The lever material brings adriven face 13 a corresponding to the actuating face 27 e-2 into anelastic contact with the actuating face 27 e-2 of the pressurizationactuating lever 27 e and extends obliquely forward so as to reciprocatelinearly toward the engaging element E intended to be pressurized overthe top face of the first ram 2. An end of the pressurizing hammer 13opposite to the inclined driven face 13 a is formed into a thin platevia a step, and the rear end corner of each thin plate portion is cutout partially so as to form a leg nipping portion 13 b. Each of the legnipping portions 13 b has a nipping face 13 c for deforming the outerridge portion of each of the pair of right and left attaching legs Linto a shape shown in FIG. 10B by pressurizing the engaging element Eformed into a Y shape shown in FIG. 10A. The front end actuating face 27e-2 of the actuating lever 27 e is perpendicular to its swing direction,and the inclined driven face 13 a is always kept in an elastic contactwith the front end actuating face 27 e-2 of the actuating portion 27 e-1by a spring force of a first spring 37 described later.

The pressurizing hammer 13 is actuated by swing of the pressurizationactuating lever 27 e and reciprocates obliquely on the top face of thefirst ram 2. When the attaching legs of the engaging element E ispressurized, it can be pressurized gradually from the engaging head ofthe engaging element E toward the front ends of the legs by disposingthe pressurizing hammers 13 obliquely in this way. That is, when theengaging element E is formed into the mountain-like shape with theforming punch 8 at the forward end stop position of the first ram 2, thepressurizing hammers 13 advance slightly so as to hold a part of theouter side faces of the attaching legs L of the engaging element E by apair of right and left leg nipping portions 13 b, and after the forminginto the mountain-like shape is ended, the hammers 13 further advance tocomplete the pressurization. At the same time when the pressurization isended, the pressurizing hammers 13 begin to retract quickly by a springforce together with retraction of the pressurization actuating lever 27e.

The chamfering actuating levers 27 h for actuating the pair of right andleft chamfering punches 113 are supported rotatably at a positionadjacent to the front side of the pressurization actuating lever 27 e bythe same fixed supporting shaft 27 k as the pressurizing hammer 13. Anactuating portion 27 h-1 is formed at the top end of the chamferingactuating lever 27 h. An oblique face of the actuating portion 27 h-1 asviewed from top is constituted of a right triangle portion placed on astraight line connecting with the preceding engaging element E′implanted to the fastener tape T two times before. The position of itsactuating face 27 h-2 is set higher by an amount corresponding to twoengaging elements E than the height of the actuating portion 27 e-1 ofthe pressurization actuating lever 27 e.

On the other hand, as shown in FIG. 5, the chamfering punch 113 isconstituted of an entirely narrow trapezoidal lever material, and anoblique portion at an end thereof constitutes an inclined driven face113 a which slides with a contact with the inclined actuating face 27h-2 of the chamfering actuating lever 27 h. Further, the front end sharpangle portion at the other end of the chamfering punch 113 is cut outpartially in parallel to the side face of the attaching leg L of thepreceding engaging element E′, and as shown in FIG. 8, a face opposingthe preceding engaging element E′ has a concave groove having atrapezoidal section in the center thereof as viewed from the side. Theinside face of the concave groove constitutes a chamfering face 113 bwhich is an important factor of the present invention. An inclined face113 b-1 of the chamfering face 113 b is set longer than the length ofthe outer ridge portion of the attaching leg L′ of the precedingengaging element E′ and higher than the height of the preceding engagingelement E′.

As shown in FIGS. 4 and 8, the formation position of the actuatingportion 27 h-1 of the chamfering actuating lever 27 h is set higher thanthe height of the actuating portion 27 e-1 of the pressurizationactuating lever 27 e and at the same height as a stop position of thepreceding engaging element E′ implanted to the fastener tape T two timesbefore. As shown in FIG. 5, the actuating face 27 h-2 at the front endof the actuating portion 27 h-1 is inclined toward a chamfering portionof the preceding engaging element E′. As shown in FIG. 3, the chamferingpunch 113 moves intersecting the pressurizing hammer 13 over thepressurizing hammer 13. As for the chamfering punch 113 at this time, asshown with an arrow in FIG. 5, the chamfering face 113 b of thechamfering punch 113 moves obliquely forward along the inclinedactuating face 27 e-2 of the chamfering actuating lever 27 h whichswings laterally to the first ram 2, and the entire chamber punch 113moves to the preceding engaging element E′. Then, the chamfering face113 b moves obliquely forward to the preceding engaging element E′ andwhen it completes the chamfering, it returns to its original positionwithout changing the posture.

According to this embodiment, the actuating faces of the pressurizinghammer 13 and the chamfering punch 113 are separated vertically, andfurther, the pressurizing hammer 13 slides on the top face of the firstram 2 while the chamfering punch 113 moves intersecting with thepressurizing hammer 113 over the same pressuring hammer 113.Consequently, the trajectories of the pressurizing hammer 13 and thechamfering punch 113 are not determined easily. Thus, according to thisembodiment, to secure the trajectory of each of the pressurizing hammer13 and the chamfering punch 113, the pressuring hammer 13 and thechamfering punch 113 are accommodated in a single housing 36. A hammerguide passage (not shown) for the pressurizing hammer 13 which extendslinearly and obliquely to the engaging element E set in the forming die5 is formed to go through the inside of the housing 36. In addition, apunch guide passage (not shown) for guiding the chamfering punch 113 isformed to go through a partition above the hammer guide passage. Thechamfering punch 13 traverses the first ram 2 at right angle to the backand forth direction and has an appropriate width from its startingposition to its chamfering position.

A first spring 37 is interposed between the hammer guide passage and thepressurizing hammer 13, and a second spring 38 is interposed between thepunch guide passage and the chamfering punch 113. The pressurizinghammer 13 and the chamfering punch 113 are actuated securely at arequired timing following up swings of the pressurization actuatinglever 27 e and the chamfering actuating lever 27 h with elastic forcesof the first and second springs 37, 38. A swing interval of the firstand chamfering actuating lever 27 e, 27 h can be converted to a largestroke by moving the leg nipping face 13 b of the pressurizing hammer 13and the chamfering face 113 b of the chamfering punch 113 obliquely, sothat an interference with such a peripheral member as the cutting punch12 can be avoided.

The operation of the pressurizing portion and chamfering portion havingthe above-described configuration will be described specifically withreference to FIGS. 6 to 9. When the third ram 27 d is located at itsretraction stop position as shown in FIGS. 6 and 8, the first and secondcam receivers 27 g, 27 j attached to the bottom end of the first andchamfering actuating levers 27 e, 27 h are in elastic contact with flatportions of the first and second cam faces 27 f, 27 i, and thepressurizing hammer 13 and the chamfering punch 113 are at a positionwhere they are retracted most (standby position). If the third ram 27 dbegins to advance, the first cam receiver 27 g first rides over thefirst cam face 27 f so as to swing the pressurization actuating lever 27e. Consequently, its actuating face 27 e-2 begins to advance in adirection of traversing the top face of the first ram 2, so that thepressurizing hammer 13 begins to move obliquely toward an engagingelement E intended to be pressurized this time. A little before thepressurizing hammer 13 moves, the formation into the mountain-like shapewith the forming punch 10 is carried out. Finally, as shown in FIG. 9,the leg nipping faces 13 b pressurize and deform the right and leftattaching legs L of the engaging element E and implant the engagingelement E to a predetermined position of the fastener tape T.

On the other hand, a little before the first cam receiver 27 g ridesover the second cam face 27 f, the second cam receiver 27 j begins toride over the second cam receiver 27 i with a slight difference of timeso as to swing the chamfering actuating lever 27 h. With this swing, theinclined drive face 113 a of the chamfering punch 113 which makes anelastic contact with the inclined actuating face 27 h-2 of thechamfering actuating lever 27 h slides along the inclined actuating face27 h-2, so that the chamfering face 113 b moves obliquely toward thepreceding engaging element E′ implanted to the fastener tape T two timesbefore. Consequently, as shown in FIGS. 7 and 9, the inclined face 113b-1 presses the upper and lower outer ridge portions of the right andleft attaching legs L′ extending from the same engaging element E′ so asto chamfer the upper and lower outer ridge portions at the same time asshown in FIG. 10C.

1. A fastener stringer continuous manufacturing method comprising: acutting step of cutting a metallic wire rod for an engaging element, themetallic wire rod molded so as to have a substantially Y-shaped section,in a lateral direction with a predetermined thickness; a step of forminga head of a cut engaging element into a mountain-like shape; an engagingelement implantation step of successively implanting attaching legs ofan engaging element which has been formed into the mountain-like shapeto a fastener tape supplied intermittently at a predetermined pitch bypressurizing with a pressurizing hammer; and a chamfering step ofchamfering an outer ridge portion of a preceding engaging elementimplanted to the fastener tape in the engaging element implantation stepwith a chamfering punch subsequent to the engaging element implantationstep.
 2. A fastener stringer continuous manufacturing apparatuscomprising: a cutting die which reciprocates in a cutting direction of ametallic wire rod for an engaging element, the metallic wire rod moldedso as to have a substantially Y-shaped section; a forming die forforming a head of the engaging element into a mountain-like shape, theforming die provided continuously on a front end in a reciprocatingdirection of the cutting die; a cutting punch which is fixed to a baseand disposed so as to freely make a sliding contact with an uppersurface of the cutting die; a forming punch for forming the head of theengaging element into the mountain-like shape, the forming punchdisposed above a mountain-like shape forming position and ascending anddescending in cooperation with the forming die; a pressurizing hammerfor successively pressurizing attaching legs of the engaging elementformed into the mountain-like shape to a fastener tape suppliedintermittently at a predetermined pitch, characterized by furtherincluding; and a pair of chamfering punches, each of which is disposedabove the pressurizing hammer at a height corresponding to a precedingengaging element implanted to the fastener tape in advance, thechamfering punch reciprocating with respect to a side face of thepreceding engaging element and having a chamfering face which chamfersouter ridge portions of right and left legs of the preceding engagingelement.
 3. The fastener stringer continuous manufacturing apparatusaccording to claim 2, wherein a reciprocation of the chamfering punch isactuated in cooperation with a drive portion of the pressurizing hammerand such an actuation is carried out by an actuating lever specializedfor the chamfering punch.
 4. The faster stringer continuousmanufacturing apparatus according to claim 2, wherein an actuating leverspecialized for chamfering is swung by a cam face, which is formed in asame drive portion in a same manner as a pressurization actuating leverand is specialized for chamfering, an actuating face of the actuatinglever and a driven face of the chamfering punch have inclined faces thatmake sliding contact with each other, and the respective inclined facesare so constructed that the chamfering punch entirely executes acomposite motion composed of a motion parallel to a swing direction ofthe actuating lever and a lateral motion in a direction perpendicular tothe swing direction of the actuating lever.
 5. The fastener stringercontinuous manufacturing apparatus according to claim 2, wherein aninclined driven face of the chamfering punch is always kept in anelastic contact with an inclined actuating face of an actuating leverunder pressure, so that it is reciprocated with sliding on the inclinedactuating face of the actuating lever by a swing of the actuating lever.